How to solve deformation defects in blow molded products in Suzhou (Part 2)

(2) The greater the difference in wall thickness between the longitudinal and radial positions of blow molded products in Suzhou, the easier it is to deform.

The shrinkage formed at the clamping line position of blow molded container products is more severe than that of adjacent positions, which means that the cooling rate in thicker areas is much slower than that in surrounding areas. The difference in cooling rate leads to different shrinkage and deformation. This defect can be solved by using both servo longitudinal wall thickness control and servo radial wall thickness control, but the equipment cost is relatively high.

Radial wall thickness control can also be replaced by trimming the core mold of the machine head, but the effect is not satisfactory. For small and medium-sized blow molded containers with flat and square shapes, the wall thickness difference of blow molded products can be reduced by slightly increasing the size of the mouth mold and core mold, in order to achieve shrinkage balance and solve deformation defects.

The influence of molding process on the deformation of Suzhou blow molding processing:

(1) The temperature of the extruder barrel, head, and mold should not be too high, as high temperatures can cause slow cooling and easy deformation of blow molded products;

(2) Insufficient cooling time during molding leads to uneven cooling and deformation of blow molded products after being molded;

(3) According to the shape requirements of the product, finely adjust the servo wall thickness curve to make the wall thickness of the product as uniform as possible;

(4) Use a chiller to supply water to the mold for circulating cooling, improving the cooling effect;

(5) Improper adjustment of the mold opening stroke parameters can cause deformation of the product during mold opening.

The impact of poor demolding on the deformation of Suzhou blow molding processing:

(1) Insufficient demolding slope of blow molded container recesses (such as under the handle, bottom grooves, etc.) can cause deformation during mold opening;

(2) Poor cooling of the mouth of blow molded containers or excessively long burrs can cause deformation during mold opening;

(3) The different sandblasting effects on the two sides of the blow molded container mold can cause deformation when the product is attached to the mold with better sandblasting during mold opening.

The impact of uneven force on the extrusion device on the deformation of Suzhou blow molding processing:

When producing blow molded board products, it is generally necessary to design an ejector device on the mold. Uneven force during ejection can cause deformation of the product. When designing the ejection device, efforts should be made to balance it with the demolding resistance. It would be better to combine pneumatic or hydraulic pressure with mechanical methods.

The impact of premature sealing of the mouth on the deformation of Suzhou blow molding processing:

The newly produced product has not been fully cooled yet. If the mating part is covered too early and fully sealed, it will cause deformation of the product due to different internal and external cooling rates and atmospheric pressure.

The influence of stress on the deformation of Suzhou blow molding processing:

Residual stress, shear stress, and cooling stress during the molding process of blow molded products in Suzhou can also cause deformation defects in blow molded products. Due to its complexity, it will not be elaborated here.

Conclusion: Different degrees of impact. The handling of deformation defects in blow molded products in Suzhou needs to be comprehensively considered and reasonably resolved, providing strong guarantees for the quality, output, and cost of blow molded product production.